25 Seedless Plants

adventitious

describes an organ that grows in an unusual place, such as a roots growing from the side of a stem

antheridium

male gametangium

archegonium

female gametangium

capsule

case of the sporangium in mosses

charophyte

other term for green algae; considered the closest relative of land plants

club mosses

earliest group of seedless vascular plants

diplontic

diploid stage is the dominant stage

embryophyte

other name for land plant; embryo is protected and nourished by the sporophyte

extant

still-living species

extinct

no-longer-existing species

fern

seedless vascular plant that produces large fronds; the most advanced group of seedless vascular plants

gametangium

structure on the gametophyte in which gametes are produced

gemma

(plural, gemmae) leaf fragment that spreads for asexual reproduction

haplodiplodontic

haploid and diploid stages alternate

haplontic

haploid stage is the dominant stage

heterosporous

produces two types of spores

homosporous

produces one type of spore

hornworts

group of non-vascular plants in which stomata appear

horsetail

seedless vascular plant characterized by joints

lignin

complex polymer impermeable to water

liverworts

most primitive group of the non-vascular plants

lycophyte

club moss

megaphyll

larger leaves with a pattern of branching veins

megaspore

female spore

microphyll

small size and simple vascular system with a single unbranched vein

microspore

male spore

mosses

group of bryophytes in which a primitive conductive system appears

non-vascular plant

plant that lacks vascular tissue, which is formed of specialized cells for the transport of water and nutrients

peat moss

Sphagnum

peristome

tissue that surrounds the opening of the capsule and allows periodic release of spores

phloem

tissue responsible for transport of sugars, proteins, and other solutes

protonema

tangle of single-celled filaments that forms from the haploid spore

rhizoids

thin filaments that anchor the plant to the substrate

seedless vascular plant

plant that does not produce seeds

seta

stalk that supports the capsule in mosses

sporocyte

diploid cell that produces spores by meiosis

sporophyll

leaf modified structurally to bear sporangia

sporopollenin

tough polymer surrounding the spore

streptophytes

group that includes green algae and land plants

strobili

cone-like structures that contain the sporangia

tracheophyte

vascular plant

vascular plant

plant containing a network of cells that conducts water and solutes through the organism

vein

bundle of vascular tissue made of xylem and phloem

whisk fern

seedless vascular plant that lost roots and leaves by reduction

xylem

tissue responsible for long-distance transport of water and nutrients